Fuel Sending Unit Noise from Contacting Tank Wall

[martincom]

I had been thinking about something like that, but wasn't sure if the added weight would impact the buoyancy. Thanks for the the reply. I'm assuming you had no issues with that.

[martincom]

I cut off a piece a bicycle inner tube and placed it in a small container of gasoline for a few days. It swelled up to near twice it's normal size. It also became much heavier from all the gasoline it absorbed. So that isn't going to work.

[Wildergarten]

I cut off a piece a bicycle inner tube and placed it in a small container of gasoline for a few days. It swelled up to near twice it's normal size. It also became much heavier from all the gasoline it absorbed. So that isn't going to work.

I'd try a wrap of 6-mil polyethylene just a hair longer than the float with a pair of appropriately-sized buna o-rings as rubber bands.

[Wildergarten]

I cut off a piece a bicycle inner tube and placed it in a small container of gasoline for a few days. It swelled up to near twice it's normal size. It also became much heavier from all the gasoline it absorbed. So that isn't going to work.

BTW, I did the specific gravity calculations for the expected added weight of the polyethylene wrapped around the float when immersed in gasoline and it came out to 1.2gm. In other words, not much in the gram scheme of things.

[martincom]

Maybe I'm over thinking this, but I was concerned about the polyethylene fatiguing from the fuel slosh, over time, and then breaking off in small pieces, plugging the fuel system.

I placed two larger O-rings around the body of the float length wise and then secured them in place with two tie wraps around the circular axis of the float. I tested the tie wraps for a few days, soaking in gasoline, without issue. We'll see how this works. I suspect I'll still hear the float making contact with the tank wall, but the O-rings should act like a rubber bumper and dampen the noise significantly.

I'm just putting the finishing touches on re-assembly after a complete re-paint and I'm waiting for the roads to dry up. Here, in the frozen tundra, they apply very liberal amounts of salt to the road surfaces in the winter. So if you have something you care about, you don't drive it in the winter and wait for the spring rains to wash the salt residue away. It rained for the last two days, so I'll venture out when things dry up.

I'm down to waiting for headliner fabric, carpet trim edge pieces from Exline (It'll be awhile on those. I'm on the waiting list.) Replacement dash speaker that should arrive tomorrow, and some stainless lifting eyes I'm going to mount on the inside box wall for cargo tie downs. They'll probably show up today, but I'll need to order some stainless bolts once I determine the length.

[Wildergarten]

Maybe I'm over thinking this, but I was concerned about the polyethylene fatiguing from the fuel slosh, over time, and then breaking off in small pieces, plugging the fuel system.

Why I was suggesting 6 mil. I was figuring it to be stiff enough not to do that. I thought about a sliced thinwall polypropylene tube for a while, or a thin hose, but I'm just not confident one could get a small piece of the right size and it was back to being a quieter rattley, not to metion the material and extra weight.
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Don't know much about how violent the slosh is, but it sure gives me headaches when the cap leaks going around bumpy corners (you should see the roads here). I was going to see if I could fit a flap in the tube to kill that. It's been done elsewhere on this site.

I placed two larger O-rings around the body of the float length wise and then secured them in place with two tie wraps around the circular axis of the float. I tested the tie wraps for a few days, soaking in gasoline, without issue. We'll see how this works. I suspect I'll still hear the float making contact with the tank wall, but the O-rings should act like a rubber bumper and dampen the noise significantly.

That would surely help.

I'm just putting the finishing touches on re-assembly after a complete re-paint and I'm waiting for the roads to dry up. Here, in the frozen tundra, they apply very liberal amounts of salt to the road surfaces in the winter. So if you have something you care about, you don't drive it in the winter and wait for the spring rains to wash the salt residue away. It rained for the last two days, so I'll venture out when things dry up.

My seasonal problem is time. I'm hand weeding 7 days a week right now. It should be warm enough to spray tomorrow.

I'm down to waiting for headliner fabric, carpet trim edge pieces from Exline (It'll be awhile on those. I'm on the waiting list.) Replacement dash speaker that should arrive tomorrow, and some stainless lifting eyes I'm going to mount on the inside box wall for cargo tie downs. They'll probably show up today, but I'll need to order some stainless bolts once I determine the length.

I'm envious at your evident rate of progress. Good show!

[martincom]

I drove it to the hardware store to pick up the stainless bolts. I didn't notice any noise from the fuel tank at all during the drive. When I returned, I rocked the truck and I could hear it bumping against the tank wall, but it is a pretty soft thump. I think the O-rings are going to be the answer.

I played around with some rubber roof material yesterday, after allowing a scrap to be submerged in a bucket of gasoline overnight. The rubber roofing was stable when exposed to gasoline. I wrapped the float in a scrap of rubber roofing and secured with tie wraps. I re-installed it enough to test the fuel gauge. As I feared, it was too heavy and the fuel gauge was no longer reading full. I verified this comparing the sending unit resistant measurements I took before removing the sending unit and again when wrapped with rubber roofing.

I'm retired and can't stand to sit still. I'm still up at 5:00AM and usually into something by 7:00AM. The 16 hour days ended by the time I was in my mid 40s and the 14 hour days by 50. I'm down to about 9 now. I learned a long time ago to recognize when I was becoming tired, because trying to push beyond that point almost always resulted in going backwards.

I don't like half finished projects, so once I start on something, i stay with it until it is done. Likewise, if I Know I won't have everything to finish, I'm very reluctant to start.

I looked at your web page. I don't have much of a green thumb and struggle just to make grass grow.

[Wildergarten]

I wrapped the float in a scrap of rubber roofing and secured with tie wraps. As I feared, it was too heavy and the fuel gauge was no longer reading full.

One could take a scrap of fuel hose, cut it in half lengthwise, and strap it on the bottom of the float with the hose extending just beyond the front end butting against the tank.